NAME

Graphics::Primitive::Component - Base graphical unit

DESCRIPTION

A Component is an entity with a graphical representation.

SYNOPSIS

my $c = Graphics::Primitive::Component->new({
  origin => Geometry::Primitive::Point->new({
      x => $x, y => $y
  }),
  width => 500, height => 350
});

LIFECYCLE

prepare

Most components do the majority of their setup in the prepare. The goal of prepare is to establish it's minimum height and width so that it can be properly positioned by a layout manager.

$driver->prepare($comp);

layout

This is not a method of Component, but a phase introduced by the use of Layout::Manager. If the component is a container then each of it's child components (even the containers) will be positioned according to the minimum height and width determined during prepare. Different layout manager implementations have different rules, so consult the documentation for each for details. After this phase has completed the origin, height and width should be set for all components.

$lm->do_layout($comp);

finalize

This final phase provides and opportunity for the component to do any final changes to it's internals before being passed to a driver for drawing. An example might be a component that draws a fleuron at it's extremities. Since the final height and width isn't known until this phase, it was impossible for it to position these internal components until now. It may even defer creation of this components until now.

It is not ok to defer all action to the finalize phase. If you do not establish a minimum hieght and width during prepare then the layout manager may not provide you with enough space to draw.

$driver->finalize($comp);

draw

Handled by Graphics::Primitive::Driver.

$driver->draw($comp);

METHODS

Constructor

new

Creates a new Component.

Instance Methods

background_color

Set this component's background color.

border

Set this component's border, which should be an instance of Border.

callback

Optional callback that is fired at the beginning of the finalize phase. This allows you to add some sort of custom code that can modify the component just before it is rendered. The only argument is the component itself.

Note that changing the position or the dimensions of the component will not re-layout the scene. You may have weird results of you manipulate the component's dimensions here.

class

Set/Get this component's class, which is an abitrary string. Graphics::Primitive has no internal use for this attribute but provides it for outside use.

color

Set this component's foreground color.

fire_callback

Method to execute this component's callback.

get_tree

Get a tree for this component. Since components are -- by definiton -- leaf nodes, this tree will only have the one member at it's root.

has_callback

Predicate that tells if this component has a callback.

height

Set this component's height.

inside_bounding_box

Returns a Rectangle that defines the edges of the 'inside' box for this component. This box is relative to the origin of the component.

inside_height

Get the height available in this container after taking away space for padding, margin and borders.

inside_width

Get the width available in this container after taking away space for padding, margin and borders.

margins

Set this component's margins, which should be an instance of Insets. Margins are the space outside the component's bounding box, as in CSS. The margins should be outside the border.

maximum_height

Set/Get this component's maximum height. Used to inform a layout manager.

maximum_width

Set/Get this component's maximum width. Used to inform a layout manager.

minimum_height

Set/Get this component's minimum height. Used to inform a layout manager.

minimum_inside_height

Get the minimum height available in this container after taking away space for padding, margin and borders.

minimum_inside_width

Get the minimum width available in this container after taking away space for padding, margin and borders.

minimum_width

Set/Get this component's minimum width. Used to inform a layout manager.

name

Set this component's name. This is not required, but may inform consumers of a component. Pay attention to that library's documentation.

origin

Set/Get the origin point for this component.

outside_height

Get the height consumed by padding, margin and borders.

outside_width

Get the width consumed by padding, margin and borders.

finalize

Method provided to give component one last opportunity to put it's contents into the provided space. Called after prepare.

padding

Set this component's padding, which should be an instance of Insets. Padding is the space inside the component's bounding box, as in CSS. This padding should be between the border and the component's content.

page

If true then this component represents stand-alone page. This informs the driver that this component (and any children) are to be renderered on a single surface. This only really makes sense in formats that have pages such as PDF of PostScript.

prepare

Method to prepare this component for drawing. This is an empty sub and is meant to be overridden by a specific implementation.

preferred_height

Set/Get this component's preferred height. Used to inform a layout manager.

preferred_width

Set/Get this component's preferred width. Used to inform a layout manager.

to_string

Get a string representation of this component in the form of:

$name $x,$y ($widthx$height)

visible

Set/Get this component's visible flag.

width

Set/Get this component's width.

AUTHOR

Cory Watson, <gphat@cpan.org>

BUGS

Please report any bugs or feature requests to bug-geometry-primitive at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Geometry-Primitive. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

COPYRIGHT & LICENSE

Copyright 2008-2009 by Cory G Watson.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.